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Biomedical subjects

A R Antonelli

Publications and source records attributed to A R Antonelli.

At least 19 recordsLinked to original sources
PubMed1991

Electric response audiometry in infants and preschool children. Long-term control of the results.

Two hundred and four infants and preschool children (mean age 2 years and 7 months +/- 9 months) with auditory impairment according to ABR and ECochG data, and 33 subjected to SVR were followed up for periods ranging from 1 year to 4 years and 6 months until a reliable conventional pure tone audiogram was obtained. One hundred and fifty-one children had conductive hearing loss, 75 sensorineural, 7 had ABR indicating disorders of the central auditory pathways, 5 were normal. Hit, false positive and false negative rates resulted as follows: 58.62%, 17.24% and 24.14% for SVR: 98.37%, 1.63% and 0% for ABR; 99.15%, 0.85% and 0% for ECochG. In the group with sensorineural hearing loss, 75% of the children gave ECochG detectable responses at 90 dB nHL, against 51.5% with ABR. With 1 kHz tonebursts, 64% of the tested subjects gave threshold responses to ECochG and 12% to ABR. The best strategy for children who failed the behavioral hearing tests, or in whom these tests were not applicable, was that based on ABR and middle ear impedance measures, complemented, when necessary, by ECochG.

Audiometry, Evoked Response↗
PubMed1991

Basement membrane components in normal, dysplastic, neoplastic laryngeal tissue and metastatic lymph nodes.

The immunohistochemical localization of the basement membrane (BM) components laminin, type IV collagen and fibronectin was analyzed in normal, dysplastic and neoplastic laryngeal specimens. The distribution of these macromolecules was also investigated in metastatic lymph nodes. A regular and continuous staining for laminin and type IV collagen was present in normal and mild dysplastic epithelium (LIN I); interruptions and reduplications were more evident in severe dysplasia (LIN III), together with an increased positivity for fibronectin in the subepithelial connective tissue. In squamous cell carcinomas the distribution of BM components was related to the degree of cellular differentiation, with a decreased immunostaining being evident in moderately and poorly differentiated carcinomas. Furthermore, the positivity for laminin and type IV collagen was influenced by the pattern of neoplastic growth, being continuous around the "pushing" border and discontinuous where the neoplastic front had an "invading" appearance. Similar changes were present in cervical metastatic lymph nodes. These observations tend to support the theory that the neoplastic growth is a cyclic process, with BM component synthesis and reabsorbtion related to the shifts of cellular metabolism.

Antibodies, Monoclonal↗
PubMed1990

Audiological findings in elderly patients with chronic renal failure.

The audiological results of 46 patients (m/f 27/19, mean age; 57.4 +/- 11.1) with chronic renal failure (CRF) undergoing dialysis were compared with those of an age- and gender-matched control group (n = 25). Mean pure tone average from 0.5 to 8 kHz was about 15 dB higher in CRF patients than in control subjects. The ABR parameters of the test group were then contrasted with those recorded in a second control group (n = 47, m/f 26/21, mean age: 56.1 +/- 11.4) matched by age, gender and degree of hearing loss (HL). After assessing the normality of the groups by the usual criteria, using the data of a sample of normal young adults, the ABR were found to be abnormal in 23.9% of the controls and in the 39.13% of the CRF patients. Wave V, I-III, III-V and I-V delays were significantly shorter in the females of the control group; in the CRF group, only the V and the I-V delays were shorter in females. The only age-dependent effect was found in the CRF sample, in which older patients had significantly longer I-III IPLD. The degree of HL influenced the latency of the waves in both groups but only the I-V IPLD was longer in CRF patients with pronounced high tone loss. The most distinguishing feature between the effects of CRF plus ageing and those of normal ageing was the lengthening of the I-III IPLD in the test group. This finding is likely to reflect a subclinical disorder of the VIII nerve function that is a part of the axonal uremic neuropathy.

Acoustic Impedance Tests↗
PubMed1989

Nasopharyngeal cysts. Report of seven cases with review of the literature.

A series of seven patients with nasopharyngeal cysts is presented. A review of the pertinent literature and a description of the clinical, radiologic, and pathologic features of these lesions are also included. The role of computed tomography in differentiating nasopharyngeal cysts from other pathologic entities, as well as the importance of surgery as an elective method of treatment, is specifically emphasized.

Adult↗
PubMed1989

Lesion detection in MS patients with and without clinical brainstem disorders: magnetic resonance imaging and brainstem auditory evoked potentials compared.

The findings of the present study can be summed up in the following points: (1) brainstem auditory evoked potentials (BAEP), as compared with magnetic resonance imaging (MRI), has a greater capacity and a lower cost in disclosing brainstem plaques both in MS patients with symptoms or signs of actual brainstem involvement and in clinically silent ones. This makes BAEP a useful technique for the neurologist, who can confirm the clinical suspicion of a brainstem lesion and follow the evolution of the disease in the patient. (2) The sensitivity of BAEP is lower than that of MRI as far as the anterior lesions of the brainstem are concerned. (3) MRI is more specific than BAEP, inasmuch as several types of injuries can alter the BAEP, while the demyelinating plaque has a specific image and can only be confused with little lacunar infarcts. (4) Plaques that produced symptoms or signs in the past can eventually disappear and be no longer detected by a subsequent MRI.

Adolescent↗
PubMed1988

A method of digital filtering to enhance the peaks of evoked potentials: application to auditory brainstem responses.

The aim of this paper is to propose a method of data processing for the analysis of evoked potentials, in particular for auditory brainstem responses. The present method has been developed to simplify and speed up the interpretation of the recordings by means of an enhancement of the response peaks. Even for experienced observers, identification of the response waves and subsequent latency measurements may sometimes constitute a difficult task, due to the presence of residual noise or to interference between the temporal waveforms of adjacent peaks and troughs. The method is implemented with a digital non-causal (zero-phase shift) filter, based on the convolution with a finite impulse response, to make the computation time compatible with the use of low-cost microcomputers. The performance is shown to be very good in several examples.

Evoked Potentials, Auditory↗
PubMed1988

Auditory evoked potentials test battery related to magnetic resonance imaging for multiple sclerosis patients.

The results of the recording of the Auditory Brainstem Responses (ABR) in 32 patient with "definite" multiple sclerosis (MS) according to Poser et al. (1983) were contrasted with the brain stem anatomic lesions evidenced by Magnetic Resonance Imaging (MRI) and with the neurologic signs and symptoms found at clinical examination (BS). Twenty-one patients showed ABR abnormalities (65.5%); in 15 cases MRI visualized demyelinization plaques in the brain stem (46.8%); 12 patients had neurological signs of brain stem involvement (37.5%) at the time of the electrophysiological and radiological assessment. When the observation was restricted to the group of 21 patients with past or present BS neurological signs, ABR sensitivity resulted 81% (17/21), while MRI obtained a value of 57% (12/21).

Adult↗
PubMed1987

Diagnosis, staging, and treatment of juvenile nasopharyngeal angiofibroma (JNA).

Nineteen patients with juvenile nasopharyngeal angiofibroma (JNA) were surgically treated with different techniques from January 1968 through December 1985. Two patients had undergone a previous operation at another hospital; all patients were males (mean age 15.4), and the most common symptom was nasal obstruction (84.2%). Lateral extension into the pterygomaxillary fossa occurred in 14 patients (73.6%), and 2 also had intracranial invasion (10.5%). In five cases, the tumor's cytosol was analyzed for hormonal receptors. Negative values for estrogen and progesterone receptors were obtained, although the content of dehydrotestosterone receptors was highly positive. These results tend to support the hypothesis of JNA's androgen-dependence. The authors emphasize the need of a preoperative staging classification based on clinicoradiological data in selecting the most adequate surgical approach. Tumors with lateral extension into the pterygomaxillary fossa can be easily removed through a midface degloving; large involvement of the infratemporal fossa requires, also, a transzygomatic dissection. In JNAs with intracranial extension a combined intracranial-extracranial approach is advisable.

Adolescent↗
PubMed1987

Audiologic diagnosis of central versus eighth nerve and cochlear auditory impairment.

122 subjects divided into four groups according to the site of lesion (cochlea, eighth nerve, brainstem and temporal lobe) were subjected to an audiometric test battery, including pure-tone sensitivity measures, recruitment testing, tone decay, Békésy audiometry, speech audiometry, stapedius reflex measures and auditory brainstem response (ABR) audiometry. The results were contrasted among the four groups by calculating several measures of test performance, including sensitivity, specificity, efficiency, A' (test performance) and plots on the receiver operating characteristic (ROC) space of pure positives versus false alarms. In the differential diagnosis between eighth nerve and cochlear site, the various measures did not rank the tests in the same order: (a) for efficiency: ABR, Békésy audiometry; (b) for A' (similarly to the analysis into the ROC space): ABR, recruitment, Békésy, stapedius reflex, speech audiometry, tone decay. In distinguishing an eighth nerve from a brainstem site, it is important to consider amount of hearing loss, presence of tinnitus, abnormal tone decay and Békésy audiometry patterns. ABR adds significant diagnostic efficiency only when waves II, III and V are detectable: a prolonged I-II interpeak interval (IPI) and a normal III-V IPI are characteristic of the eighth nerve site. ABR gives good diagnostic support in the intrinsic brainstem lesions by suggesting changes in the generator sites of the component waves. The audiometric diagnosis of temporal lobe lesions involving the auditory cortex still relies upon speech audiometry: tests specifically designed for this purpose by Bocca and Calearo and by Jerger - i.e. the 'sensitized sentences' and the identification of synthetic sentences under ipsi- or contralateral competing message - are commendable for their sensitivity and efficiency in distinguishing brainstem from temporal lobe sites. In brainstem sites, the most affected ear is ipsilateral to the lesion for ABR, but contralateral for speech audiometry.

Adolescent↗
PubMed1986

Auditory brain stem response test battery for multiple sclerosis patients: evaluation of test findings and assessment of diagnostic criteria.

A battery of auditory brain stem response (ABR) tests has been used to evaluate 39 multiple sclerosis (MS) subjects (9 with probable, 8 with possible, 6 with suspected and 16 with definite MS, according to conventional classification of the disease). Test battery included evaluation of ABR waveform, latencies and interpeak intervals, test-retest variability, rate-induced ABR changes, binaural increase of wave-V amplitude and effect of ipsilateral masking with broad-band noise. Test results allowed a measure of the sensitivity, specificity and efficiency of each test in the battery. The high efficiency values thus obtained validated each test in the battery when normals were compared with definite MS patients. No single test, however, proved to be sufficient--by itself--to reliably distinguish subjects with earlier stages of the disease, suggesting that a combined evaluation of tests is necessary to fit better the clinical classification. When compared with 'conventional' ABR analysis, 'sensitized' ABR tests--i.e. the measures of test-retest variability, binaural increase of wave-V amplitude and the effect of ipsilateral broad-band noise masking--showed higher percentages of positive results in subjects with no clinical signs of brainstem and midbrain involvement. Sensitized tests therefore appeared more suitable to reveal a brainstem subclinical involvement.

Adolescent↗